DRI scientists investigate effectiveness of heat warnings along US-Mexico border
RENO, NEV. AUG 25, 2020
Anthropology Meteorology Climatology Population Heath
Above: Aerial view of California’s Imperial Valley, where daytime temperatures during summer months can reach as high as 120 degrees. Credit: Thomas Barrat/Shutterstock.com
Featured research by DRI’s Kristin VanderMolen, Ben Hatchett, Erick Bandala, and Tamara Wall
In July and August, daytime temperatures along parts of the US-Mexico border can reach as high as 120 degrees – more than 20 degrees above normal human body temperature. For agricultural workers and others who live and work in the region, exposure to these extreme high temperatures can result in serious health impacts including heat cramps, heat exhaustion, heat stroke, and heat-related death.
Although the National Weather Service and public health organizations issue heat warnings to communicate risk during extreme heat events, heat-related illness and death are still common among vulnerable populations. Now, a group of DRI scientists led by Kristin VanderMolen, Ph.D., Assistant Research Professor with DRI’s Division of Atmospheric Sciences, is trying to figure out why.
“With the continued increase in episodes of extreme heat and heat waves, there has been an increase in warning messaging programs, yet there continue to be high numbers of heat-related illness and death in communities along the US-Mexico border,” VanderMolen said. “So, there’s this question – if agencies are doing all of this messaging, and people are still getting sick and even dying, then what’s going on?”
An agricultural field in California’s Imperial Valley, where DRI researchers are exploring questions about heat messaging and vulnerability in populations of agricultural workers and others who are vulnerable to heat-related illness and death.
Credit: Winthrop Brookhouse/Shutterstock.com
Assessing heat messaging: An interdisciplinary approach
In 2018, VanderMolen and colleagues Ben Hatchett, Ph.D., Erick Bandala, Ph.D., and Tamara Wall, Ph.D. received funding from NOAA’s International Research and Applications Project (IRAP) to explore questions about heat messaging and vulnerability in two pairs of US-Mexico border cities, San Diego-Tijuana and Calexico-Mexicali. Collectively these areas form the boundaries of the Cali-Baja Bi-national Megaregion. This unique transboundary location integrates the economies of the United States and Mexico, exporting approximately $24.3 billion worth of goods and services each year.
With expertise in the areas of anthropology, meteorology, climatology, and population health, this interdisciplinary team of researchers is now working on this problem from several angles. They are using climate data to characterize and assess past heat extremes as well as using long-range weather forecasts and climate projections to help improve the ability to put out advance messaging about future heat waves. They are working to identify and map populations that are particularly vulnerable to extreme heat and are collaborating with local agencies to understand why people may or may not take protective action during heat waves.
From initial conversations with local civic organizations and public health agencies, the team has learned that the reasons people may not be following heat warnings are complex. Recommended actions such as “stay indoors and seek air-conditioned buildings,” or “take longer and more frequent breaks,” may not be realistic for agricultural workers or others who don’t have access to air-conditioned spaces. There can even be negative consequences for those who choose to seek medical help.
“A big piece of the story that we’ve heard from some of the independent groups that work with agricultural workers in the region is that if someone gets sick and doesn’t show up for work, they can lose their job,” Hatchett explained. “If they go to the hospital and somebody sees them or hears about it, they can lose their job. There are some really big issues related to people not feeling okay with trying to get the help they need.”
“There is evidence to suggest that cases of heat-related illness and death are underreported, probably severely underreported,” VanderMolen added. “The demographics of the individuals for documented cases don’t reflect the population demographics overall. We know that there are a lot of inequalities in that area that may get in the way of people reporting illness.”
A map of summer maximum near-surface temperatures over the 30-year period from 1981–2010 shows that Imperial Valley (at the border between Mexico and the southeastern corner of California) is the hottest place in in North America, with an average maximum temperature from June to August of 40° Celsius (104° Fahrenheit). Data is from the North American Regional Reanalysis.
Credit: Ben Hatchett/DRI
COVID-19 complications and next steps
Originally, VanderMolen was planning to travel to the US-Mexico border this summer to do one-on-one interviews with members of vulnerable populations, but the COVID-19 pandemic has resulted in unforeseen complications.
Imperial County has been hit very hard by COVID-19, compounding the effects of extreme heat for the vulnerable populations that VanderMolen and her team hope to work with. The pandemic has also made it unfeasible to travel to the region to do face-to-face interviews, and has created challenges in coordinating with local agencies that are now overwhelmed in their efforts to address COVID-19.
“It’s a really interesting place and time to do this work because there are questions about what it means to be on stay-at-home orders and limited travel orders when it’s 114 degrees outside and you don’t have reliable air conditioning or its cost is prohibitive,” VanderMolen said. “At the same time, because they’re so overwhelmed right now with caseload, most folks in the area can’t really afford to address issues beyond COVID-19.”
As the research team works to navigate a path forward that is safe for both the interviewers and interviewees, they remain committed to developing information that will help vulnerable populations along the border.
“I hope that the information we provide is something decision-makers can use to make the right decision or create legislation that can help protect workers in the field, or at least call attention to the kind of inequalities and risk that the people there are being exposed to,” Bandala said. “Or, if we can produce information to change the mindset of the people to start thinking of themselves as a population at risk, and put more attention on the heat warnings, that will suffice for me to feel satisfied with the results of our research.”
The US-Mexico border is just one of many places around the globe where heat-related illness is a problem, added Hatchett – and many of those places happen to be where a lot of our food is grown or where important industries are located.
“I think this is a somewhat ubiquitous problem around the planet. We have these really important places that are susceptible to environmental extremes and these people that we rely on to have these regions be productive in terms of agriculture or industry. Unfortunately, those people are often the most susceptible and underserved populations to these compound environmental hazards,” Hatchett said. “It’s so easy to forget them, but one of the goals of this project is really to bring to light the importance of aiming much-needed resources at trying to help those populations and those places.”
For more information on the members of this DRI research team, please visit:
Microplastics, plastic fragments that are smaller than 5 mm in any dimension, have been found in ecosystems worldwide. These emerging contaminants are even in environments that are supposed to be free from human contact, such as Antarctica and the deep ocean floor, and their toxic properties make them a significant environmental hazard.
“After the first acknowledgement of microplastics in the early 2000s, their presence in the environment has raised ever-increasing concerns because of their effects on organisms and ecosystems, and because approximately 1.5 million tons of microplastics are estimated to be released into aquatic environments every year,” explains Dr. Erick Bandala, the principal investigator of this project, which also includes Dr. Menake Piyasena from New Mexico Tech, graduate research assistants Adam Clurman and Ahdee Zeidman, and summer intern Yajahira Dircio. “Unfortunately, very little is known about the capability of engineered separation and/or degradation technologies to remove this highly ubiquitous contaminant.”
Commercial products that are manufactured to contain microplastics—such as personal care and pharmaceutical products, industrial abrasives, drilling fluids, and 3D printing products—are the primary sources of microplastics. However, the degradation of plastic debris can also generate microplastics.
“Wastewater treatment plant effluents are the main pathway for microplastics to be released into aquatic environments,” Bandala says. “Although the microplastic removal rate of a conventional wastewater treatment plant is reported to be in the range of 73 to 79 percent, the treated effluent can carry as much as 220,000 to 1.5 million microplastic particles per day.”
Yajahira Dircio, a student at Rancho High School and summer intern on the project, is preparing hydrochar from MPs using a sand band. Credit: Erick Bandala/DRI
In recent years, the effects microplastics have been found to have on aquatic species and their unknown effects on human health have increased concerns about their presence in water sources.
“Because conventional water treatment processes are unable to effectively eliminate microplastics in water, developing new technologies that can separate them from effluents and prevent their release into the environment is a high priority to protect water quality and water security,” Bandala says.
For this project, the researchers will use acoustic focusing and electrocoagulation to separate microplastics from freshwater effluents and determine the removal process mechanisms.
“Acoustic standing waves are a fast, noncontact, gentle particlemanipulation technique for microfluidic conditions that have emerged as a promising new technology for the purification, separation, and concentration of beads and biological cell samples,” Bandala explains.
The researchers will also assess the efficacy of using electrocoagulation to remove MPs from wastewater.
“Electrocoagulation has several significant advantages to conventional chemical coagulation, such as it increases treatment efficiency, generates less sludge, requires less space, and prevents chemical storage,” Bandala adds. “It has been proven to be highly efficient in removing contaminants. Our research group has used it for water defluoridation and to pretreat effluents that were heavily contaminated with petrochemicals.”
Because microplastics are increasingly detected in freshwater, it is even more important to find effective water treatment process that remove them.
“Although ultrafiltration, or microfiltration, have microplastic removal efficiencies as high as 99.4 percent, they also have high operational and maintenance costs and require skilled operators,” Bandala explains. “Finding efficient, costeffective methods to separate microplastics from freshwater effluents is critical to preventing population exposure.”
Adam Clurman, an undergraduate student at Nevada State College, is conducting the electrocoagulation experiments for the project. Credit: Erick Bandala
Another challenge that microplastics present is how to dispose of them once they are removed from water. For this project, the researchers will use advanced oxidation processes (AOPs) as complementary processes to degrade the plastic waste after it has been separated from the wastewater. Advanced oxidation processes are an eco-friendly way to degrade organic compounds. In previous projects, the research group has tested the capability of these processes to degrade a wide variety of dissolved organic contaminants in water.
“Advanced oxidation processes have been used to degrade organics and have shown high cost-efficiency and short detention time compared with conventional water treatment processes,” Bandala explains. “Using AOPs to degrade microplastics will not only be an interesting challenge because of the complexity of their polymeric chains, but also because these contaminants are suspended in water and treating contaminants in a different phase in water using AOPs has not yet been reported.”
Maintaining the quality of water sources is an increasing issue, particularly in arid and semiarid regions with rapidly growing populations, such as Nevada.
“Desert Research Institute has reported the presence of MPs in places such as the Sierra Nevada and Lake Tahoe, which are the origin of several drinking water supply systems in Nevada,” Bandala explains. “We live in a region with a moderate-high water stress and as Nevadans, we need to protect our water sources from contamination to ensure the sustainable development of our communities.”
This story was originally written for the Nevada Water Resources Research Institute (NWRRI) Summer 2020 Newsletter. Success and the dedication to quality research have established DRI’s Division of Hydrologic Sciences (DHS) as the Nevada Water Resources Research Institute (NWRRI) under the Water Resources Research Act of 1984 (as amended). The work conducted through the NWRRI program is supported by the U.S. Geological Survey under Grant/Cooperative Agreement No. G16AP00069.
Reno, NV (April 7, 2020): The Desert Research Institute (DRI) proudly announced today that Dr. Naresh Kumar has been selected to lead the Institute’s Division of Atmospheric Sciences.
Dr. Kumar comes to DRI from the Electric Power Research Institute (EPRI) in Palo Alto, California, where he served for more than 20 years as a senior program manager and environmental leader in the areas of air quality, climate change, renewable energy, and multimedia sciences.
“I am extremely pleased to join DRI and honored to lead its Division of Atmospheric Sciences,” said Dr. Kumar. “DRI has an excellent reputation for conducting the highest quality of science for the betterment of society, and I am committed to maintaining that excellence while expanding research and solutions to solve emerging environmental challenges.”
While at EPRI, Dr. Kumar oversaw a diverse research portfolio, while inspiring teams of scientists and the development of multi-disciplinary programs and international collaborations. His technical leadership and success fostering key relationships helped EPRI significantly grow and expand its program offerings in air quality and health, climate change, and environmental aspects of renewables research beyond market expectations.
“Dr. Kumar brings an impressive record of accomplishments to DRI,” said Dr. Kumud Acharya, Interim President of DRI. “He has a depth of experience and relationships across a broad network of national and international scientific experts in top academic institutes, as well as our national labs, many federal and state agencies, private industry, and well-known environmental groups.”
Dr. Kumar has a Ph.D. in Mechanical Engineering from Carnegie Mellon University, an MBA from the Walter Haas School of Business at UC Berkeley, an M.S. in Mechanical Engineering from UC Santa Barbara, and a B.Tech. in Mechanical Engineering from the Indian Institute of Technology, Kharagpur, India.
For more information about the DRI Foundation or DRI please visit www.dri.edu
The Desert Research Institute (DRI) is a recognized world leader in basic and applied interdisciplinary research. Committed to scientific excellence and integrity, DRI faculty, students, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge, supported Nevada’s diversifying economy, provided science-based educational opportunities, and informed policy makers, business leaders, and community members. With campuses in Reno and Las Vegas, DRI serves as the non-profit research arm of the Nevada System of Higher Education.
Photo: Hotter temperatures and longer, more frequent heat waves are linked to a rising number of deaths in the Las Vegas Valley over the last 10 years.
Las Vegas, Nev. (June 4, 2019) – Over the last several decades, extreme heat events around the world—particularly in the North American Southwest—have gotten hotter, occurred more frequently, and lasted longer. These trends pose significant health risks to the growing number of people making cities like Las Vegas home.
A new study by faculty and undergraduate students at the Desert Research Institute (DRI), Nevada State College, and Universidad de Las Americas Puebla traces the relationship between extreme heat and mortality rates, identifying a clear correlation between heat wave episodes and heat-related deaths in Las Vegas over the last ten years.
“Current climate change projections show an increased likelihood of extreme temperature events in the Las Vegas area over the next several years,” explained Erick Bandala, Ph.D., assistant research professor at DRI and lead author on the study. “Understanding recent extreme heat trends and their relationship to health hazards is essential to protecting vulnerable populations from risk in the future.”
Erick Bandala, PhD (left), shows a graduate student the data he and his team analyzed for this study.
Urban areas of the Southwest are of particular concern because several factors compound the health-related risks of extreme heat events. The heat-absorbing properties of common materials like asphalt exacerbate already high temperatures in cities (called the urban heat island effect), particularly at night. What’s more, populations in cities like Las Vegas are growing rapidly, especially among those 55 and older, which means that more and more people are exposed to risk.
In this study, the research team analyzed two measures of extreme heat—heat index and excess heat factor—for the Las Vegas metropolitan area in the June, July, and August months from 2007 to 2016. Heat index (HI) accounts for how the human body reacts to surface temperature and relative humidity. Excess heat factor measures (EHF) heat wave intensity in relation to historic temperature trends to account for how acclimated the public is to a given temperature threshold. Because both HI and EHF incorporate the human body’s response to extreme heat, they are ideal metrics for assessing public health impacts, and both were shown to rise over the study period.
The annual average of severe heat events per year in Las Vegas also showed significant increases in this study, from an average of 3.3 events per year from 2007-2009 to 4.7 per year in the 2010-2016 period. These findings match historic trends, which show a steady increase in severity and frequency of excess heat in Las Vegas since 1980.
Strikingly, the number of heat-related deaths in Las Vegas map onto these trends: as heat wave intensity increases, the number of heat-related deaths does, too.
Heat Index (HI) and Excess Heat Factor (EHF) are metrics that go beyond just temperature to also account for the human body’s response to heat. This study found that rising trends in these measures tracked closely with the number of heat-related deaths in Las Vegas.
“From 2007 to 2016, there have been 437 heat-related deaths in Las Vegas, with the greatest number of those deaths occurring in 2016,” explained Bandala. “Interestingly, 2016 also shows one of the highest heat index measures over the last 35 years. This shows a clear relationship between increasingly intense heat events in our area and public health effects.”
Bandala’s team found that the subpopulation particularly at risk of heat-related deaths is adults over 50 years old—76% of the heat-related deaths in the study period were individuals in this subpopulation. Of the deaths in this group, almost all individuals also showed evidence of pre-existing heart disease. Researchers note that these findings are highly significant given that the population of adults over 50 in Las Vegas is increasing, with more retirees choosing Clark County as a retirement destination.
Only 23% of heat related deaths occurred in the subpopulation of adults aged 20 to 50 years; interestingly, the most common pre-existing condition for this group was drug and alcohol use. More research is needed to understand how heat is impacting this segment of the population, Bandala noted, because though the number of deaths in this group is comparatively smaller, it is still nearly one quarter of heat-related deaths in the Las Vegas Valley. Additionally, this subpopulation includes economically active adults.
With more intense, more frequent, and longer lasting heat events projected in the coming years, the research team hopes that the trends identified in this study can assist local decision-makers in taking steps to protect the most vulnerable groups in Las Vegas.
“This research helps us better understand the connection between the climate changes we’ve experienced in Las Vegas and their impact to public health over the last 35 years,” Bandala said. “Ideally, this data analysis will help our community adapt to the changes yet to come.”
The full study, titled “Extreme heat and mortality rates in Las Vegas, Nevada: inter-annual variations and thresholds”, is published in the International Journal of Environmental Science and Technology. The study abstract and references are available here: https://link.springer.com/article/10.1007%2Fs13762-019-02357-9
This study is based on work supported in part by the National Science Foundation, NASA, and the Desert Research Institute. Other members of the project team include Kebret Kebede, Nikole Jonsson, Rebecca Murray, and Destiny Green, all of Nevada State College; John Mejia of DRI; and Polioptro Martinez Austria of the Universidad de Las Americas Puebla.
Emissions from wildland fires and biomass fuel use contribute to regional air pollution events, global scale radiative forcing and climate change, and cause severe health effects. However, the role of organic compounds in these processes is still largely unknown and underestimated.
For this reason, the OAL team performs combustion experiments in the DRI’s combustion chamber to characterize in details chemical and physical properties of biomass-burning emissions, especially organic compounds.
Moreover, to study atmospheric aging of combustion pollutants, OAL students operate the oxidation the flow reactor (OFR) that needs only 1-2 minutes to mimic 7 days of oxidation in real atmospheric conditions.
This work is supported by NSF (grant no. AGS-1544425, P.I.: V. Samburova, co-PIs: H. Moosmüller and A. Khlystov), NASA (grant no. NNX15AI48G, P.I.: H. Moosmüller, co-P.I.: V. Samburova), and DRI’s Wildland Fire Science Center (WFSC)
The OAL team use Malaysian peat fuel for a combustion experiment.
Students Chiranjivi Bhattarai, Michaelene (Miki) Iaukea-Lum, and Deep Sengupta preparing eucalyptus for burning experiment in the DRI’s combustion chamber.
TIGF filters sampled with biomass-burning emissions from combustion of Malaysian peat.
OAL’s oxidation flow reactor
OAL “biomass-burning” team
OAL Assistant Research Professor Vera Samburova is starting the combustion experiment with Malaysian peat fuel.
Drs. Andrey Khlystov and Vera Samburova participated in the DRI Day at the NV Legislature today. They met with Senator Heidi Gansert, Assemblywomen Heidi Ann Swank and Lisa Krasner, and educated many members of NV State Legislature on dangers of flavoring compounds in e-cigarettes. Dr. Khlystov attended the recognition of DRI from the floor of the NV Senate by the State Senator Heidi Gansert.
The Organic Analytical Lab was well represented at the Society for Research on Nicotine and Tobacco 2019 Annual Meeting in San Francisco. Drs. Andrey Khlystov, Vera Samburova and Yeongkwon Son attended the meeting and Yeong presented three (!!!) posters. Please visit https://cdn.ymaws.com/www.srnt.org/resource/resmgr/SRNT19_Abstracts.pdf to see the abstracts (POS2-8, POS2-17 and POS4-47). The posters generated a lot of interest and created new opportunities for collaboration with governmental agencies and educational institutions.
Our paper “Physical and chemical characterization of aerosol in fresh and aged emissions from open combustion of biomass fuels”, Aerosol Science and Technology, vol 52, No 11, by Bhattarai C. et al., senior author A. Khlystov, (https://doi.org/10.1080/02786826.2018.1498585) is among the Top Ten most downloaded since November 2018! Well done!
OAL graduate students, Deep Sengupta and Chiranjivi Bhattarai have been selected to become Teaching Assistants in UNR Physics for Scientists and Engineers courses! Deep is a TA for three different groups taking course PHYS 181L; Chiranjivi is a TA in PHYS 180L and PHYS 180 recitation. Congratulations and good luck, Chiranjivi and Deep!
Erick Bandala, Ph.D., is an assistant research professor of environmental science with the Division of Hydrologic Sciences at the Desert Research Institute in Las Vegas. Erick specializes in research related to water quality and water treatment, including the use of nanomaterials in developing new water treatment technologies. He is originally from Mexico, and holds a bachelor’s degree in chemical engineering from Veracruz State University, a master’s degree in organic chemistry from Morelos State University, and a Ph.D. in Engineering from the National Autonomous University of Mexico. Erick has been a member of the DRI community since 2016, when he moved to Las Vegas to begin his current job. In his free time, Erick says that he enjoys doing nothing – a passion that is not shared by his wife of nearly 30 years, who enjoys doing many things.
DRI: What do you do here at DRI?
EB: My work here is to develop advanced technologies for water treatment, such as processes that can deal with the pollutants in the water that are not removed by conventional water treatment methods.
DRI: We understand that a lot of your work involves nanomaterials. What are nanomaterials, and how do you use them in your research?
EB: Nanomaterials are materials that are so small that if you compare the size of one of these materials with a basketball, it’s like comparing the size of the basketball with the size of the earth. These nano-sized materials have applications in many different fields.
In my case, what I’m doing with the nanomaterials is using them to promote reactions in the water that can produce chemical species capable of destroying contaminants. Not only to remove the contaminants, but to destroy them from the water.
Erick Bandala, Ph.D. at work in DRI’s Environmental Engineering Lab. Credit: Dave Becker, Nevada Momentum.
DRI: What type of contaminants do you hope to remove? Can you tell us about one of your projects?
EB: Right now, we are trying to get nanoparticles made of something called zerovalent iron, which is iron with no charge on it. We are planning to use this to remove antibiotics from water. As you know, we all use antibiotics every now and then. And when you use them, the antibiotics get into your body and you will probably only use about 15 percent of the total amount that is present. Whatever remains is discarded with your feces or urine into the wastewater.
Once the wastewater arrives at the water treatment plant, the conventional water treatment processes will probably not be able to remove the antibiotic. So, the antibiotic passes through the wastewater treatment system and keeps going with the treated effluent. In the case of Las Vegas for example, it goes back to Lake Mead. This is a problem, because we are learning now that bacteria can become resistant to antibiotics just by exposure – and when bacteria in the environment become resistant to the antibiotics, there is no way for people to treat infections.
So, in our work, we hope to use nanoparticles to destroy the contaminants in the wastewater. At the moment we are just running some trials in the lab, but we eventually hope to run the experiment at pilot level to see if we can treat wastewater coming back from plants to the lake, and ensure that we will not have these contaminants going back to our environment.
Another part of my research is on how to use solar energy to remove contaminants from water. This way you can save some money by using an energy source that is common in Nevada, widely available. We have a lot of sunshine here.
Information about nanomaterials from DRI’s Environmental Engineering Lab. Credit: Dave Becker, Nevada Momentum.
DRI: How did you become interested in working on water treatment and water quality?
EB: My very first job was working in a research institute in Mexico that was devoted entirely to water. The group that I arrived to work with was dealing with water quality and treatment in wastewater and drinking water. So, I started down this path just because it was available and I needed the job – but my plan was to spent two years working on this and now it has been more than 25 years. I feel very passionate about this field of work. I feel like this is the way that I have to try to help people, and I love it.
DRI: You are originally from Mexico. What brought you to DRI?
EB: When the position at DRI opened three years ago, I started learning about the water related issues that Nevada and particularly Las Vegas was facing, and was fascinated. The city gets its water supply from Lake Mead then sends treated wastewater back to the lake — so having almost 100 percent recycling of the water is something that caught my attention immediately. Not only because it’s wonderful, but that it may also result in other problems like the recycling of some pollutants that you probably don’t want in your drinking water. That idea really captured me. So I decided to apply for the job, and have had three years of great fun trying to deal all of those problems and promote some solutions that may help to deal with the reality we’re facing in Las Vegas. Reno is not that different – we all need water when we’re living in places where water resources are so scarce. I was really intrigued by how to deal with all of these problems and how I might help.
Erick Bandala (second from left) and his colleagues from DRI’s Environmental Engineering Lab.
OAL scientists Drs. Vera Samburova and Yeongkwon Son attended the 2018 Nevada Public Health Association annual conference in Las Vegas. They gave presentations on potential hazards of e-cigarette use to the broad audience of health care providers, clinicians, educators, and researchers. The talks generated a lot of interest among the attendees and initiated productive discussions. Well done, Yeong and Vera!
The recent OAL publication“Aldehydes in Exhaled Breath during E-cigarette Vaping: Pilot Study Results” in the open access journal Toxics is highlighted in the DRI news release! Please read the full story here.
Dr. Andrey Khlystov was invited to give a keynote speech at the 25th International Conference on Aerosol Science and Technology (ICAST) in Tainan, Taiwan. His presentation “Light-absorbing organic carbon in biomass burning aerosols, its properties and transformation” highlighted NSF-sponsored research done at the OAL.
Deep Sengupta presented a poster “Semi-Volatile Organic Compounds in Fresh and Laboratory-Aged Biomass Burning Aerosols” and gave a talk “Estimation of Snow Albedo Reduction due to Deposition of Light Absorbing Aerosols Using a Monte Carlo Radiative Transfer Model” at the 10th International Aerosol Conference in St.Louis, USA. Well done, Deep!!
The latest OAL publication by Vera Samburova et al. on aldehydes in exhaled breath attracted the attention of all major local media outlets! Please click “Continue reading” to see image gallery and enable links to videos.
Congratulations to Chiranjivi Bhattarai who successfully defended his Master of Science in Atmospheric Chemistry thesis on June 27th, 2018, at the Desert Research Institute! Chiranjivi has joined the OAL in fall 2014, and conducted a detailed study of “Physical and Chemical Characterization of Fresh and Aged Biomass Burning Emissions” under the supervision of Dr. Andrey Khlystov. Results of this study will be published in the journal Aerosol Science and Technology, stay tuned! Update Feb 2019: the paper was published in November 2018 (AS&T vol 52 No 11) and is among the Top Ten downloaded despite its limited accessibility!
A DRI team (DAS Executive Director Marc Pitchford and OAL scientists Drs. Andrey Khlystov and Vera Samburova) traveled to Carson City to meet with the officials from the Nevada Department of Health and Human Services. Dr. Khlystov presented results of OAL’s study on the hazardous levels of toxic aldehydes in e-cigarette flavorings and the new OAL’s findings on emissions from very popular JUUL e-cigarettes. While having relatively low carbon monoxide and formaldehyde emissions, JUUL pods subject users to very high concentrations of nicotine, a known addictive substance. Active discussion followed the presentation, and a visit by NV DHHS representative to DRI is expected in the near future. Nevada leads the nation in juvenile e-cigarette use, causing serious concern among state health officials. E-cigarette emissions research done by the OAL at DRI helps to educate and empower the lawmakers.
Dave Campbell, Associate Research Scientist at the DRI’s Division of Atmospheric Sciences and the Organic Analytical Lab member, participated in a 5-week long monitoring campaign near Paramount, CA, sponsored by the South Coast Air Quality Management District and conducted in collaboration with Aerodyne Research Inc.
The Nevada System of Higher Education (NSHE) Board of Regents this week awarded Vera Samburova, Ph.D., an assistant research professor of atmospheric chemistry and air pollution at DRI, with its annual Rising Researcher Award.
She was recognized for her early-career accomplishments and leading a new and exciting area of research at DRI looking at inhalation and indoor air quality related health effects. The honor is given annually to one NSHE faculty member from DRI, UNR, and UNLV.
Reno, Nev. (Thursday, March 1, 2018) – The Nevada System of Higher Education (NSHE) Board of Regents this week awarded Vera Samburova, Ph.D., an assistant research professor of atmospheric chemistry and air pollution at DRI, with its annual Rising Researcher Award.
She was recognized for her early-career accomplishments and leading a new and exciting area of research at DRI looking at inhalation and indoor air quality related health effects. The honor is given annually to one NSHE faculty member from DRI, UNR, and UNLV.
As a member of the DRI’s Organic Analysis Laboratory, Samburova’s research focuses on the collection and analysis of atmospheric organic species, characterization and quantification of organic emissions from various sources like biomass burning and fossil fuels.
She recently initiated an internally funded research project investigating the emissions from e-cigarettes. Her research team found that the aerosols (commonly called vapors) produced by flavored e-cigarettes liquids contain dangerous levels of hazardous chemicals known to cause cancer in humans. Their research was published in Environmental Science & Technology (ES&T), a journal of the American Chemical Society.
“The health impacts of e-cigarettes are still widely unknown and not researched,” said Samburova. “I am incredibly honored to be recognized for this important work and everything that our team at DRI has done to advance this important and emerging field of research.”
Samburova has authored a total of 35 peer-reviewed publications, 20 since joining DRI, and seven of which she was the first author. She has served as a principal investigator, and co-principal investigator, and a key personnel/scientist for 15 projects that have received over $2 million in external research funding.
She is also actively involved in the Atmospheric Sciences Graduate Program at the University of Nevada, Reno where she has taught classes every year starting in 2008 and has been the Deputy Director of that program for the last five years.
Samburova received her Ph.D. in Environmental Organic Chemistry from the Swiss Federal Institute of Technology, Zurich in 2007, after which she was recruited at Desert Research Institute as a Post Doc and subsequently transitioned to an Assistant Research Professor.
Dr. Andrey Khlystov has been named a “2018 New Investigator Award Winner for Best Abstract” by the Society for Research on Nicotine & Tobacco for his presentation “The Effect of Puff Topography and Power Settings on Aldehyde and Carbon Monoxide in E-cigarette Aerosols”. The award was presented at the Society’s annual meeting in Baltimore, MD. Dr. Khlystov is the Director of the Organic Analytical Laboratory and a Research Professor of Atmospheric Chemistry at DRI. Two other OAL members presented posters at the SRNT meeting: Dr. Vera Samburova (“Carbonyl Compounds in Exhaled E-cigarette Aerosols”) and Dr. Yeongkwon Son (“Indoor Air Quality in Electronic Cigarette Vape Shops”).
In the Organic Analytic Laboratory at DRI, our main specialty is sampling and detailed chemical analysis of organic air pollutants. Our team has more than 20 years of experience in this area.
E-cigarette research is new for us but involves similar sampling and analytical techniques. Having seen advertisements for e-cigarettes that claimed they are safe because liquids contain only FDA approved ingredients, we decided to apply our expertise to see what is in e-cigarette vapors. This resulted in the publication of the first set of results concerning the role of flavorings in aldehyde formation during vaping.
Following the publication of our paper, we received a lot of attention from media, the blogosphere, and individual vapers. This shows the importance of the problem and we are pleased to have made a contribution to the ongoing discussion of the pros and cons of vaping.
While the news coverage was generally accurate, we noticed some misunderstanding and misrepresentation of the study, especially in comment sections of media articles and on some blogs. For example, we were amazed to see some commenters suggesting that our study was sponsored by the tobacco industry. This is completely untrue. This was an internally funded study. None of us, nor the Desert Research Institute has any connection to the tobacco industry.
A recent blog post by Dr. Farsalinos was also brought to my attention. In his post, Dr. Farsalinos states that our “results contradict previous research on aldehyde emissions” and he makes other assertions that I would like to address here in more detail. By making this statement, Dr. Farsalinos revealed that (a) he is not up-to-date with the current literature, and (b) has not read our paper carefully, because we explicitly compare our results to other studies.
Our paper states (from the top of the right column of page four): “For example, maximal formaldehyde emissions observed in this study are approximately 2−7 times lower than the steady-state emissions measured by Sleiman et al.,9 who reported values ranging from 13000 to 48200 ng/mg. In terms of emissions per puff, our formaldehyde data [0.12−50 μg/puff (Table S3)] are comparable to values of 0.05−50 μg/puff reported by Gillman et al.6 and 30−100 μg/puff reported by Sleiman et al.9”
Yes, the highest observed concentrations in our study, which seem to have caused disbelief in some such as Dr. Farsalinos, are actually several times lower than those reported in another recent study (Sleiman et al.). In Sleiman et al., it is reported that the first few puffs significantly underestimate aldehyde emissions as the coil temperature needs time to come to steady state. Most if not all of the previous studies that reported low aldehyde concentrations did not include warm-up puffs. This is also discussed in our paper.
Our study also clearly states – “our results do not suggest that PG or VG produces no aldehydes, but that flavoring compounds are responsible for the main part of the emitted toxic aldehydes. Nondetects for unflavored liquids reported in this study are likely due to the small number of puffs that we have used in our measurements. By collecting more puffs per measurement, we could have quantified emissions for unflavored liquids. This quantification, however, is of minor consequence, as the flavored liquids produce significantly more aldehydes than unflavored ones do” (top of the left column on page 5).
We are not contesting the contribution of PG/VG to aldehyde formation. Our point is that flavorings cause significantly higher emissions.
The standard excuse (written about here – http://www.nejm.org/doi/full/10.1056/NEJMc1502242) of a “dry-puff” to explain aldehyde emissions cannot be applied to our study.
There is only one peer-reviewed paper that asserts that high aldehyde concentrations are due to dry puffs only and that these cause aversion in users. That paper was reviewed in just 11 days and methodological problems have been identified by other researchers – see a review by Shihadeh et al. here http://onlinelibrary.wiley.com/doi/10.1111/add.13066/full.
As was discussed above, the evidence is mounting that aldehyde levels in e-cigarette vapors could be dangerously high.
While we do agree with Dr. Farsalinos that the strength of science lies in reproducibility of experimental results and we wish anyone success in reproducing our study, we strongly believe that science requires impartiality and an open mind. Statements such as “I should note that it is impossible to convincingly identify something that went wrong in this study” are derogatory and assume that our study is wrong.
We would also suggest Dr. Farsalinos reproduce studies by Sleiman et al., Gillman et al., and Jensen et al.
It should be also noted that aldehydes and their DNPH adducts are chemically unstable. Experience and utmost care are required to obtain accurate results.
While we are not interested in proving or disproving Dr. Farsalinos’ dry puff study, we have collected some preliminary data that contradicts conclusions of that study regarding high aldehyde levels causing an “unpleasant” sensation during vaping.
We are collecting data for secondary aldehyde exposure associated with vaping. To estimate secondary emissions, we collected exhaled breath from three research volunteers, who were asked to vape as they normally do in a real-life scenario. The results are shown in the unpublished graph below (DO NOT CITE).
The levels are comparable to what we have measured per puff. One volunteer produced higher concentrations because a different device was used. None of our volunteers complained about anything unpleasant during their vaping.
We continue working on characterizing other pollutants in e-cigarette vapors and have data collaborating the effect of flavoring additives we reported in the ES&T.
Stay tuned for more exciting results and important research findings from our team!
Scientists stress need for thorough research into flavored e-liquids
RENO – Building on more than 30 years of air quality research in some of the most polluted urban environments on Earth, a team of atmospheric scientists at the Desert Research Institute (DRI) has turned their attention toward the growing e-cigarette industry and the unidentified effects of vaping on human health.New research published today in Environmental Science & Technology (ES&T), a journal of the American Chemical Society, reports that the aerosols (commonly called vapors) produced by flavored e-cigarettes liquids contain dangerous levels of hazardous chemicals known to cause cancer in humans.
“How these flavoring compounds in e-cigarette liquids affect the chemical composition and toxicity of the vapor that e-cigarettes produce is practically unknown,” explained Andrey Khlystov, Ph.D., an associate research professor of atmospheric sciences at DRI. “Our results show that production of toxic aldehydes is exponentially dependent on the concentration of flavoring compounds.”
E-cigarette liquids have been marketed in nearly 8,000 different flavors, according to a 2014 report from the World Health Organization. Recent reports have shown that many flavors, such as Gummy Bear, Tutti Fruitty, Bubble Gum, etc., were found to be especially appealing to adolescents and young adults.
The U.S. Food and Drug Administration (FDA) reports that 16-percent of high school and 5.3-percent of middle school students were current users of e-cigarettes in 2015, making e-cigarettes the most commonly used tobacco product among youth for the second consecutive year. In 2014, 12.6-percent of U.S. adults had ever tried an e-cigarette and about 3.7-percent of adults used e-cigarettes daily or some days.
Khlystov and his colleagues measured concentrations of 12 aldehydes in aerosols produced by three common e-cigarette devices.
To determine whether the flavoring additives affected aldehyde production during vaping, five flavored e-liquids were tested in each device. In addition, two unflavored e-liquids were also tested.
“To determine the specific role of the flavoring compounds we fixed all important parameters that could affect aldehyde production and varied only the type and concentration of flavors,” explained Vera Samburova, Ph.D., an assistant research professor of chemistry at DRI.
Samburova added that the devices used in the study represented three of the most common types of e-cigarettes – bottom and top coil clearomizers, and a cartomizer.
The study avoided any variation in puff topography (e.g., puff volume, puff velocity, interval between puffs) by utilizing a controlled sampling system that simulated the most common vaping conditions. E-cigarette vapor was produced from each device by a four-second, 40-ml controlled puff, with 30-second resting periods between puffs. The e-cigarette devices were manually operated to replicate real-life conditions and all samples were collected in triplicate to verify and confirm results. Specific care was taken to avoid “dry puff” conditions.
e-cigarettes provide further proof that the flavoring compounds, not the carrier e-liquid solvents (most commonly propylene glycol and/or vegetable glycerin) dominated production of aldehydes during vaping, the authors performed a series of experiments in which a test flavored e-liquid was diluted with different amounts of the unflavored e-liquid. Liquids with higher flavor content produced larger amounts of aldehydes due to pyrolysis of the flavoring compounds.
In all experiments, the amount of aldehydes produced by the flavored e-cigarette liquids exceeded the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs) for hazardous chemical exposure.
“One puff of any of the flavored e-liquids that we tested exposes the smoker to unacceptably dangerous levels of these aldehydes, most of which originates from thermal decomposition of the flavoring compounds,” said Khlystov. “These results demonstrate the need for further, thorough investigations of the effects of flavoring additives on the formation of aldehydes and other toxic compounds in e-cigarette vapors.”
This research was independantly funded by the Desert Research Institute and conducted in DRI’s Organic Analytical Laboratory located in Reno, Nevada.
“Flavoring Compounds Dominate Toxic Aldehyde Production During E-cigarette Vaping”
DOI # – 10.1021/acs.est.6b05145 – http://pubs.acs.org/doi/abs/10.1021/acs.est.6b05145
DRI scientists used a controlled sampling system to simulate the most common vaping conditions. E-cigarette vapor was produced from each device by a four-second, 40-ml controlled puff, with 30-second resting periods between puffs. Credit DRI.
DRI scientists measured concentrations of 12 aldehydes in aerosols produced by three common e-cigarette devices shown here. Credit DRI
The Desert Research Institute (DRI) is a world leader in environmental sciences through the application of knowledge and technologies to improve people’s lives throughout Nevada and the world. Learn more at www.dri.edu
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